Mode choice model for public transport (ferry, fast ship and aircraft) study case: Kupang - Rote Route

The mode of transportation that travels from Kupang City to Rote Ndao Regency is currently a mode of sea transportation and air transportation. This study aims to find out user information based on its mode choices and model it in the multinomial log function, besides that it's hoped that this result can be used as a reference in determining policies that improve functions and facilities for mobilizing people, goods and services carried out on the Kupang to Rote.Data analysis was carried out in two ways, namely with descriptive statistical analysis techniques to explain the characteristics of respondents and multinomial logistic regression analysis to create a model of mode transportation selection for Kupang-Rote service. The results of the study showed that users of transportation services from Kupang to Rote, generally men prefer to use ferry boats while women prefer to use fast boats. The characteristics of respondents is age 20-39 years. While the factors that influence the choice of transportation are the influence of luggage, weather and comfort. For the selection model, the probability of a speedboat is 34.65%,the probability of choosing a ferry is 42.96%, and the probability of choosing an aircraft is 22.3%.

Nocturnal isoprene oxidation over the Northeast United States in summer and its impact on reactive nitrogen partitioning and secondary organic aerosol

Isoprene is the largest single VOC emission to the atmosphere. Although it is primarily oxidized photochemically during daylight hours, late-day emissions that remain in the atmosphere at sunset undergo oxidation by NO3 in regionally polluted areas with large NOx levels. A recent aircraft study examined isoprene and its nocturnal oxidants in a series of night flights across the Northeast US, a region with large emissions of both isoprene and NOx. Substantial amounts of isoprene that were observed after dark were strongly anticorrelated with measured NO3 and were the most important factor determining the lifetime of this radical. The products of photochemical oxidation of isoprene, methyl vinyl ketone and methacrolein, were more uniformly distributed, and served as tracers for the presence of isoprene at sunset, prior to its oxidation by NO3. Comparison of a determination of the mass of isoprene oxidized in darkness by NO3 to a calculation of integrated isoprene emissions showed that large amounts (>20%) of emitted isoprene may undergo nocturnal oxidation in this region. Organic nitrates produced from the NO3+isoprene reaction, though not directly measured, were estimated to account for 2–9% of total reactive nitrogen and 7–31% of other long-lived organic nitrates such as PAN. The mass of isoprene oxidized by NO3 was comparable to and correlated with the organic aerosol loading for flights with relatively low organic aerosol background. The contribution of nocturnal isoprene oxidation to secondary organic aerosol was determined in the range 1–17%, and isoprene SOA mass derived from NO3 was calculated to exceed that due to OH by approximately 50%.